Smelting and refining process.



vm. 813,824. PATENTBD FEB. 27, 1906.

13.0.POLLARD. v

SMELTING AND REFINING PROCESS.

APPLICATION FILED MAY 21, 1904.

3 3HBETS-SHEET 1 INVE/VTOR XE IZQS 6%!212172 WITNESSES.-

By Mg A770RNEY$ 3 SHEETS-SHEET 2.

7&0 v mu m m u K T uy Wm B No. 813,824. P'ATENTED FEB. 27, 1906.

B. 0. POLLARD. SMELTING AND REPINING PROCESS. APPLICATION FILED MAY 21, 1904.

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PATENTED 153.27, 1906.

E. O. POLLARR SMELTING AND REPINING PROCESS.

APiLIOATION FILED MAY 21, 1904.

lNl/E/VTOR E7208 CfaZZarZ In I W/T/VESSES: I i

ATTORNEYS i To all wh'ontit concern).-

, This'in-vention Enos 0. ROLLARD,. or SEATTLE, WASHINGTON.

Specification of Letters Patent.

" smisa r me AND net-mine. PROCESS.

Patented Feb. 27, 1906.

Be it known --that I, ENOS C. POLLARD, a

: citizen of the UnitedStates, and a resident of Seattle, in the county of King and State of Washin on, have invented a .new and Improved melting and-Refining Process, of which the following is a full, clear, and exact description. Y relates to a novel process for'thedirect and continuous conversion of ores and matte into a metallic roduet. It is especially adapted to the sulfi ores of copper, and it mafi also be em loyed to special advantage wit 1 nickel .an ores. *i I Matte may :be treated b "the process in the samemanner as ores, and ence in thefollowcopper nickel 'ing description and claims the term ore may be taken to include matte in such instances as the term ore has no special significance. I 3

The rime object of the invention is-to bring aiibut not only the smelting of the ores, but the refining or conversion of the matte to produce. the finished metallicproduetby a continuous operation, in which all of the steps are-independent and rformed in immediate'suecession, thus ma g a single concrete process do the work heretofore generally rformed by separateprocesses, and thereby saving in numerous respects, as will be obvrous.-. I

In the ordinary process of reducing sulfid ores of copper and other metalssuch as those of Butte, Montana, and vicinity, for examplethe ore is treated to five'separate successive operations before reaching the sta e (fblistcm-opper) that I attain by one.- n the first of these operations, that of mechanical. concentration to eliminate the large excess of silica occurring in the ore,a rea t deal of metal is wasted by being carrie away in the material thrown out. The most co'nservative estimates of this waste place it at twenty-five per cent. of the value of metai ultimately recovered. Of course an equal waste of the original gold and-silver, which occur in appreciable quantities in these ores,

takes place. The co per carried by thetailings is not equally istributed through the mass, but appears in. graduallyrincreasing percentage, so that were the process. of. mechanical concentration reducedv only the less wasteful part would -',be performed. If it were reduced one-half, only about one-quar- Application as in, 21. 1004. steam. 209.001.

ter of the loss would take place. If it were reduced only one-tenth, (or to nine-tenths of its present ex tent,) the saving would be nineteen per cent. of the total loss or four and three-fourths per cent. of the total amount produced, an amount that would well cover the entire cost of treatment. The amount of silica will be greatly increased also, as well as the amount of iron saved from the pyritcs.

properties of all If we can utilize the fluxinig pass a bisilicate the iron in smelting an slag, (represented,forexample, b FeOSi(),,)

a further saving will be accomp ished. The next operation is to roast or calcine the ore, which requires a very extensive plant and some labor and fuel merely to drive off sulfur and oxidize the iron, so as to render it fit to slag off the remaining silica, thereby destroying fuel which in itself would be sufficient .to perform the next operation, smelting. Here the iron, which has been'oxidized to F0 0 or Fe -,O is reduced to FeO at an expense for coke. The matte is allowed to cool and is broken up and remeltcd in a cupola ailil is finally taken to the converter. Here the cold air has to be heated to the tem ri'aturc of the mass, and this entails an ar ditional loss.- A large amount of iron which might have served to slag, some of the silica must now be slagged by silica taken from the converter-lining. Manyexperiments have been made to obviate this necessity, the results of in the converter until the greater'part of the iron is sco rifie d, when it must be removed; otherwise it will foam and fill the entire converter and be expelled from its throat. This 5 foaming is more marked in thin slags and is made use of in an important manner in my new rocess, as will be seen. When the blast is finished, the total amount of copper found 'is considerably less than that m the ore at the,start. Losses have occurred in the, concentration, was stated above, in-the roasting and 1n the smelting, when t e ulverulent nature of the ore permits th b ast to carry some of'it from the furnace.

It is the main object of my invention to reduce these losses bwelimina'ting the roasting entirely by usin more compact material in the furnace and y other ste s which will be further pointed out hereina ter. This new ienerally stated my new process is executed as follows: The ore, with a proper admixture of llux, is fused to produce a matte, and this, with the resultant slag, is drawn oil and allowed to set tle, the lighter and relatively valueless portions of the slag being run otl to the dump, afterwhich the matte and remaining slag is subjected to the action of a blast of air, which bessemeriacs the matte, pro- I ducing a finished metallic product and foreing the metals oxidized by the blast into the l oft slag, and which by its kinetic energy in addii each side of the converter, as best illustrated in Figs. 1 and 3.

that to efiervescence produced in a manner to be described is caused to force the slaw up into the furfiace in wh ch the ore is smelter,

the slag there bathing the matte and the silicious coin onent of the ore absorbing a portion thereoi and passing otl' therewith, to be settled as before After once starting the process is the slag and matte beingkept in stead movement so long as operations are to be performed thereon, the ore being continually explained.

eptup continuously,

' dam l) is composed ot a wateracket covered charged into the melting-Yuma(re, the lighter 1 portions of the sla being steadily drawn otl" to the dump and t e related or finished mctallic product being drawn out of the-cycle of operations when the proper degree of refinement is attained.

Reference is to be. had to the accompanying drawings, forming a part of this spccitication, illustrating an apparatus by means of which my invention may be practiced. in which simnar characters of reference indicate corresponding parts in all the views.

Figure l is a vertical section on the line 1 l of Fig. .3 of a preferred form of my apparatus. Fig. l is a vertical section-on the line 12 .3 of Fig. i. Fig. 3 is a sectional plan on the line 3 3 of Fig. 1. Fig. 4 is a vertical section on the line 4 4 of Fig. 3. Fig. 5 is a vertical sec.- tion on the line 5 5 of Fig 3.

F indicates the cupola-turnaco, C the converter, and B the box or base thereof. iudicates the settler or lore-hearth, and R indicates the receiver for the refined copper or other metal. These parts are Stl1POI'i0tl on a suitable l'raming which will not he specifically described, since in itself it forms no partof my invention.

F indicates the boot. or bowl at the bottom of the cupola-turnace; and into this the throat of the converter empties.

t Reference to Fig 3 will show that the fur once, and converter are transversely clone gated, which a rangement. I consider best in practice, although it is not essential. From the bottom portion or boot. F of thehirnace a passage P extends, (see Figs. 1 and 5,) this )assa e running downward and discharging into the bottom of the settler at l. A see.-

- ond passage l passes from the settler at a the compartment (lto settle to the bottom point above the discharge or lower and P of the passage I, this passageP disc-liar ing mto the lower part of the converter. %E ee Figs. 1, 2, and 3.) A passage P extends from the bottom of the box or base 13 intothe receiver R. The box or base 8 is-supported on jacks 1t) and comprises an;outcr shell 11, of metal deeply lined with ganister or other non-eonduct-ing material 12, supplemented by a thin shell of basic material 13. as inagnesite, on the inner surlace. I

14* and H" indicate the bostle-pipes for sup ilying' the blast to the twyers 15 and 15 he converter. 'lhese twyers are arranged just above the box B and in two rows, one at The converter is divided into two compartments 0' and Q by two separate dams D and Li), the latter and upper one ofwhieh is so with non-com uctin material sup )lemented liya basic lining and extends from t 1e highest )ossible level of the matte. to withih afe iv inches ol'the hott'om, thus allowing the matte which has been'blown up to white metal in and pass into the compartment C where it is I blown to libs-tern" The dam l) is com ing coating autoxmitically) extending from a.

point slightly below the top of the d am I) to the roof of the converter. The level of the matte in the compartment C will be several inches lower than that in the compartment C on account of its greater specific gravity.

The twyers t5 and 25* are conneeted to the separate hustle-pipes i4 and 14, which allow of independent regulation of blast-pres sure in each set of twyers. f

The 'eonverter is constructed of metallic shells 16, forming a water-jacket completely surrounding the converter and lined with a deep cover ng 17, ot ganister or other nonconductingmaterial, to the upperlevel of the matte-surhtce, which'lining' s supplemented bv a thin shell'of basic. linin x' The inuerside .ot the shell 16 has projecting rivets or books (indicated at 38) whereby to hold the lining II in place. The cupola-furnace is contraeted toward its bottom and is formed of inner and outer walls 19, similar to and, if desired, eontinuat'ions of the walls or shells 16., 'lhese walls It) also form a Water-jacket.

the stack. and, if desired, rails 21 maybe arranged as usual to carry the charging-car, thus permittin" the cupola -turnace to be charged from the top in the usual manner. The twyers 23 of the cupolaI-turnace are lo- Ab'o've the cup-ola-furnaee is a conduit .20, leading to "cated 'ingone row on thatside of the furnace opposite. the converter and a suificient disshells 26 at its sides, forming a water-jacket tothe level ofthe bottom of the passage P with brick 27 or the like and provided with .a lidcornprising a metallic shell 28 and a brick 1 portions of the matte which accumulate in 'the settler .and which lie too low to be foi' cooling the same.

, r and cold water is caused to circulate througha cast-iron'shell lined with brick or ganister or the rials.

"settlcr foridrawing ofl the slag, and in this .which'th'eslag is allowed to accumulate in the vsettler maybe re ulated, it being understood tance'above the hearth of the furnace to allow quiet subsidence of the molten mate? "The settler S is preferably supported on casters 24 and is constructed of a metallic shell 25 at its bottom and inner and outer surrounding the settler. The settler is lined .1i-ii g' "30 indicates a vertical slot formed in the slot placeda vertically-adjustable damplate 31, provided with an orifice 32. By raising and lowering this plate the level at that when the sag reaches the level of the orifice 32 it oasses'ofl" to the dump.

33' indicates a tap for drawing off the heavier passed intothe converter through the passage P". The passages P and P are formed of inner and outer shells not only constituting the passages, but also forming Water-jackets 34 indicates a removable covering at the top of'the passage P, which facilitates introducing an instrument into the passage to clear out clinkers and other 'obstructions. The receiver R is formed of a metallic shell 35,"lined with non-conducting material 36, such as fire-brick or the like, and this receiver is formed with a vertical slot 37, extending throughout the length ofone its walls. This slot is ada ted for the passage of the refined product 0 the apparatus and in operation should be damm" up to the desired height by means of clay or brick. (Indicated at 38 in F' 3.) This is protected by a slab of meta 39. -,The.height of this dam in the slot 37 regulatesthc height of the metal in the receiverfR'aI'id of the matteand slag in the con verter. The blast of is course supplied by any suitable blowing engine, (not shown',)

out-the various water-jackets by apparatus whichm ay be of any suitable sort.

, The roofof the converter is in sections, whichv may be easily removed, and consists of 40, supportedppon hollow cast-iron arches 41, whiehmayhe water-cooled. 'The roof is held in place by keys 42, driven into slots cast in the upper part of the rrches 41.

The non-coinlucting lining'of the converter 1 is employed to revent the low temperature i of the water jac ctfrorn chilling the contents of. theiconverter. It is desirable to keep inasmuch as the molten converter content K must furnish the heat to maintain itsliquidit and at the same time heat the enormous vo nine of air passing through it.' Further, the reactions take place mm: 1 more rapidly-and effectually at a hi h temperature. An additional lining of in 'sible basic material, such as magnesite, which-is not attacked by the metallic oxids produced in bessemerizing the matte, is interposed between the silicious lining and the molten contents of the converter in order to protect that silicious lining against the corrosive action of those metallic oxids. The flaring shape of the lower part of the converter operates to preserve the lining against the attack of the metallic oxide by receding from the upwardpath of the blast, and the oxids therefore ascend to the supernatant layer of slag and are absorbed by that medium, as contradistinguished from being absorbed by the lining of the converter.

1 will now explain in specific terms the manner of carrying out the process, using the apparatus above explained. In the following description let it be assumed, for example, that the before-mentioned sulfid ores of copper are being worked. A charge of ore comprising the sullids of copper, nickel, cobalt, or in some instances lead, together with the sulfid ores of iron and perhaps others, with a silicious slag, is introduced into the furnace F and fused therein. When fuel is mixed with the charge, the fusion is accomplished by the aid of light blasts from the twyers 23. The matte formed by this fusion flows through the passa e P into the settler S, filling that portion ofthe same which lies below the passage P and overflowing through the same into the converter As there is no attempt to eliminate any of the metals in the furnace, this matte will contain all of them, except such as are volatilized. The slag upon fusing follows the course taken by the matte, flowing over the same into the converter. When the level of the matte rises above the twyers 15 15*, the blast through these twyers should be turned on. The sulfur in the matte will unite with the oxygen ofthe blast to form sulfur dioxid, which escapes through the matte and the supernatant layer of, slag and passes out through the furnace F. The iron of the matte will unite with the oxygen of the blast these contents at the highest possible heat, i is en cicnt room left below the top of the Ind passage P to allow the slag to enter freely. This passage P may be positioned at any point desired in the converter, and the level of the matte. is determined by the lieight of the dam 38 in the receiver It. The height of the slag in the converter is'regulated by the outlet 32.

The conversion of the matte is continued in the compartment C of the converter until white metal (a more or less inipure form of cuprous sulfid, Cu S) settles in the bottom and fills the converter to the level of the bottom of the dam I), thus preventing the passage of lower-grade matte into the compartment There need be no rigid rule as to the exact degree of concentration of this matte, as a small quantity of iron could be oxidized without interfering with the foaming of the slag, for which this separate conmartment is especially designed. As a rule, however, it would be better to blow the matte as high as or higher than' the' white metal in the compartment C. Subjected to an independently-controlled blast in the compartment 0 the remaining sulfur is oxidized and, incidentally, cuprous oxid is formed, which when mixed with cuprous sultid produces the following reaction: 2611 0 Cu S 6(lu 50,. The sulfur dioxid escapes in minute bubbles, causing the slag to foam and occupy greater space, and hence be speciticall y lighter than the same slag prior to foaming. Experience with converters shows that unless the matte be skimmed of slag when the iron has been entirely oxidized the slag will in a short time occupy from three to four times the space originally 'occupied. With this device (assuming that there is about eightcei'i inches of matte above the twyers in the compartment C" and twelve inches of slag above the matte) as soon as the slag occupies more than double its former space it will begin to flow up out of the converter into the furnace F and be poured directly into the melting zone of the furnace, which flow will be accelerated by the kinetic energy or moving force of the upward-flowing blast. in this connection the difference between the kinetic energy and static pressure of the blast should be clearly observed. The static pressure acts equally and tends to raise the level of the slag in the settler above that in the converter and of the matte in the receiver above the matte in the converter. The kinetic energy or moving force of the blast. producing an upward current in the converter helps to carry the slag with it in the manner explained. As the slag from the solid contents of the same, consisting of white-hot silica and such of the sulfids as have escaped fusion. Owing to the low grade of the matte being converted, both converter enters the cupola it bathes the slag and gases are at a high heat. The hot basic slag from the converter attacks the hot matte falling through the slag silica remaining iii the eupola after the fusion 6 5 also tends to rid the slag of an shots or' prills of matte. suspended t erein.

the bubbles therein to.be d1srupted, and the slag is thereupon reduced to its original homogeneous or compact state. The hot fid falling through it, cleansing the slag of 7o any copper which may ave been scorified in the slag Cu OSiO FeS Cu S FeOSiO The scouring action of this fall of matte;

The also causes escapmgxgases give up their remaining ox 8o gen to t e fuel, still further intensifyirigt e heat and fusing the metallic sulfids readily. The slag, together with the matte formed of the molten sulfids, esca es passage P into the settler ing the converter through the passage P becomes (FeO) SiO by the addition of a molecule of FeO, and then on enterin the through the Ihave thus' 5 shown-that a molecule of FeO(SiO entercupola becomes 2FeO(SiO by the ad ition i of one molecule of SiO and on enterin the settler through the passa e P apart 0 the FeO(SiO escapes to the ump, whilethe remainder returns to the converter to be subjected again to the reactions explained. The 9 5 v blister-copper will flow into. the receiver R, whence it is drawn ofl as it accumulates. The lighter portions of the slag run off continually thr'ough the outlet 32 to the dump.

After the operation of the process has been .lOO

started the calculated ore mixture should, be regularly charged into the cupola. This mixture should be calculated to produce a silicious slag-that is to say, the silica present in the charge should exceed the amount 10,5

required to produce a unisilicate when combined with all of the iron and other bases in Y the charge. In other words, the calculated slag should have the formula SiO in which R represents other metals in the charge other than those to be recovered from the matte produced- The extent of this excess of silica must l'cle-' pend upon local conditions; but there should i always be an excess, because the slagxpassed ig5 out to the dump is of the sametenor-in silica as that used for fluxing the ferrous oxid in the converter, and good results cannot be obtained by producing a slag in the converter (RO) ,SiO the iron and no containing a greater proportion of bases than I 20- a unisilicate. In order to reduce the reactions to a chemical equation, Ihave hereinbefore considered 1; e slag discharged to be a bisilicate'FeO (Si In fact, thiswillbea very good sla cases; but I 0 not confine m self to any specific proportion of silica. The metallic contents ofthe ore may be an miggture.

to adopt in the majority of 12 5 the varioussulfids of iron and copper often bearing gold and silver in commercially profitable quantities and usually various other metallic sulfidsas impurities. In addition to the metallic contents of the ore there may often be cases where lime or other basic flux may -be profitably added to the mixture that is to say, when there is a large excess of silica in the ore.

Fuel'may be a ded as the local conditions require. The necessity of a silicious slag presumes a higher temperature than is necessa when a more basic slag is passed. It shoul be remembered in this connection that an excess of fuel works no In my process no such condition applies.

It will be noted that the blast-pressure within the converter will cause a homogeneous or compact liquid to rise higher in the receiver It than in the converter; but the a metal in the receiver approaches morenearly i the top and escapes'to the dum to metallic copper than that in the converter, and hence it is of greater specific gravity, which will tend to ofl'set the blast-press '.l.he blast-pressure will also cause a com act slag to risea few inches higher in the orehearth than in the converter. This back or static pressure of the blast is due to the obstruction offered by the ore volume in the cupola to the passage of the escaping ases and by no means equals the pressure 0 th blast as it issues from the twyers.

, The dischar e of-the slag through the orifice 32 of the sett er does not take lace, immediately upon the entry of the 's a intothe; settler, time being allowed for the 's ag to settle, and the heavier and richer portions are thus preci itated to the bottom and the lighter an relatively valueless slag passes to During the time consumed by thiss'ettling operation heat is lost from the slag by radiatibn and the heatin of the waterin the jacket; but this loss 0' heat is divided between the two streams of slag mentioned above, and sup osing the two streams of sla to be equal the oss in the escaping stream 0 slag is only one-half of what'it would be were a part of the slag not returned to the converter. This is of great importance in view of the fact that when slag is near its melting-point raising its temperature a few degrees makes a vast difference in its fluidity and the consequent thoroughness with which the matte will sepa ratetherefrom. The loss of' heat'is'princi pally through the walls of the settler, and the liquidity of the escaping stream. In view of the same specific gravity, and, further, that the sla escapes at a higher tem erature uable contents. The heavier portions of the compounds settle in the bottom of the 'settler and fill the same to the level of. the .passage P, whereupon they should be withforms an indepen ent source of profit.

The contents of the com 'artment C will be, on the bottom, a layer 0 metallic copper containing the gold and silver of the ore and some other im urities. This 'will be distinctly se arate from the overlying body of matte, which will be approximatel sulfid eS, which percentage wil be less near Above this matte there will float a layer of sla the level of which will be the same as the of the slag in the compartment C, be.- cau'se the two bodies are connected by the passage between the two dams. The level of the matte in this compartment will be lower than that, in the compartment C and will be such that the combined hydrostatic heads of its matte and its sla will balance those in the com artment C, he receiver R will be fille" with etallic co per to a height which will balance the com med pressures of the matte, slag, and blast in compartment -.C.

raising or, lowering the dam-plate 39, while o iris turned on, through the twyers :15 and 15 of a sufficient -press'urev to penetrate the the body of. ore in the furnace F.

notlimit my invention thereto, butthat it relation especially to copper .ores, it is to be :understog lbutltha others capable of similar action, saeh'iasiithose of t within the scope of my invention.

slag nearest the walls beiiig cooled below matte with more or less impure lead and leaddrawn by tappin from the hole 33. This the bottom' and away from the dam 1).;

This'mressulp and level may be adjustedv by.

temperature of that'in the middle of the set-i6 5 tler will sink to the bottom-and join thestream backto the converter, while the hot central portion-rises and escapes, thus futvther intensifying the heat and consequent of the fact that the slags passed inethis process are necessarily silicious and that a silicious slag is not only lighter, butseparates from. the matte more rapidly than a basic slag than is usua the slags produced by t 's process are exceptionally clean and free from .val

C with, erhaps, a small percenta e of zerrdusi too the dhpth' of the layer of slag in the settler S l and the compartments C and C may be 'ad- I {usted with reference to the level ofthe matte phraising or lowering the outlet'32. A blast overlying matte and slag and escape-through While lhaveillustrated a specific of "apparatus, it is to be understood that ldo rib may beembodied in many other for ms, f {Al-1 though '-I have described the .inventiortwithf that a is 'not limited thereto, .5

e copper group," come j Having thus described my invention,-

claim as new and desire to secure by Letters Patent- 1. A continuous process of bessemerizing mattes, consistin in passing a stream of siliabsorb the products of besscmerizing blasts, discharging this slag from the bessemerizing region into contact with silicious material to dissolve the silica and incor )orate it in the I slag, discharging a part-of the slag, and returningthc remainder of the slag to the bessemerizing regions while still in a molten condition.

2. A process of bessemerizing mattes, con- .15 sisting in passing afistream of silicious slag over the matte" in the besscmerizing regions, discharging the slag from the bessemerizing region into contact with silicious material continuously, discharging a part of the slag, and returning the remainder thereof to the bessemerizingregions. '3. A continuous, process '13? hcssemerizing copper mattes, consisting in passing a stream of silicious slag over the hiasemerizing reions, discharging this slag into contact with 'errous sulfid to reduce any copper carried by the slag to a subsuliid, discharging a part of the slag, and returning the remainder there of together withferrous and euprous sulfids, to the hessemerizing regions to supply matte to the bessemerising regions.

4. A continuous cyclical process of reducing ore containing sulfur, consisting in melting it in the presence of a flux to produce matte, separating matte and sing from the ore, passing a stream of slag over the matte, besscmerizingthe matte in the presence of the sla returning a part of the slag to the creme ting regions to fllIIllSl'l a flux for ad ditional ore, andreturning the slag with new matte to the bcssemcrizing regions.

'5, The process of bessemerizin consisting in passim a stream of silicious s a over the material while bcing 'subjectcd. to essemerizing blasts, causing a mixture of cuprous i"o'xid and c 1 prous suhid to react beneath a column of molten slag, thereby causing the formation of sulfur dioxid within the slag and "fori'iug the slag by the llynamic energy due go totheeli'ervescehce thus produced, together with the kinetic energy of the besscmorizing f hlasts, 'into' theprcsence of ore being fused in a higher plane than that 'from which it was -i introduced into the converter, and thereafter causing the matteiani' siliciousslag to flow a? into the'bessenierizingregionby the force of lahvitan J ,,.L' I 1i: 6. -'A'process-of bessemerizing consisting in Y passing astr'eanrof silicious' slag over the ma- 6o t'eriai rrhilefbeing subjected to bessemerizing blasts, causing'a reaction beneath a column of ino-ltenslag to produce a gas withinthe 1 force the latter by the dynamic cious slag over-t 2e bcssemerizing regions to 'mcrizing blasts into the presence of ore being fused, and thereafter causing the matte and silicious slag to flow back into the bessemeiizing region by the force of gravity.

7. The process of bessemerizim matte, which consists in maintaining over the matte a layer of liquid silicious slag obtained from fusing the ore, assing a, blast of air through the matte anc through said supernatant layer of slag, and in expelling the slag from the presence of the matte by the combined agency of the kinetic energy of'the bessemerizing blast and elfervescence due'to oxidizing the sulfur in the matte.

8. The recess of hessemerizing matte, consisting in passing a stream of silicious slag over the matte in the besscmerizing region, continuously discharging the slag from the bessemerizing region into contact with a silicious material, and returning a part of the slag to the bessemerizing region.

9. A continuous cyclical )rocess of reducing copper ores containing sulfur, consistingin melting them in the presence of a flux to pro-v duce-matte, separating matte and slag from 99 the ore, passing a stream of slag over the matte, bessemerizing the matte in the presence of slag, drawing oil the lighter portion ofthe slag, returning a part of the slag to the ore-smelting regions in a higher plane than the bessemerizing regions, and returning the slag from the melting regions with new matte to the besseinerizing regions.

10. A process of refining metals, which comprises the fusing of a charge of ore con- Ioo taimng sulfur and an excess of silica, retaining all the iron of the ore in the matte, running off and settling the resultant matte'and silicious slag, and returning portions of the slag into the presence of the ore. 1o 5 11. A process of refining metals, which consists in fusinr a charge of ore containing cop )er, iron, sulfur and an excess of silica, wit rout oxidizing the iron and the major portion of the sul or, running oil and settling 1 lo the resultant matte and slag, and returning portions of the slag into the presence of the ore.

12. A process of refining metals, comprising the fusing of ore containing sulfur, the bessemerizing of the matte produced, and the cyclicalcirculation of a stream of slag alternately t'o 'the fusing and bessemerizing regions.

13. A process of refining sulfid copper ores 1 20 which comprises fusing the metallic contents of the ore in the; presence of a flux and retaining in the matte the iron and the major portion of the sulfur contained in the ore in an unoxidized condition and bessemerizing the 25 resulting material.

1- A process of refining metals which comi In testimony whereof I have signed my prises fusing ore. containing sulfur, copper name to this specification in the presence of and iron, bessemerizing the matte produced, I two subscribing witnesses. continuously running off the lighter portions EN OS C. POLLARD. 5 of the slag, and cyclically circulating a. Witnesses:

stream of richer slag alternately to the fusing RICHARD PENNARD, and bessemerizing regions. J. L. BELL. 

